687866491 has 8 divisors (see below), whose sum is σ = 741003984. Its totient is φ = 634761120.

The previous prime is 687866483. The next prime is 687866503. The reversal of 687866491 is 194668786.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 687866491 - 2³ = 687866483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687866441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54576 + ... + 65986.

It is an arithmetic number, because the mean of its divisors is an integer number (92625498).

Almost surely, 2^687866491 is an apocalyptic number.

687866491 is a deficient number, since it is larger than the sum of its proper divisors (53137493).

687866491 is a wasteful number, since it uses less digits than its factorization.

687866491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16061.

The product of its digits is 3483648, while the sum is 55.

The square root of 687866491 is about 26227.2089822764. The cubic root of 687866491 is about 882.7438851714.

The spelling of 687866491 in words is "six hundred eighty-seven million, eight hundred sixty-six thousand, four hundred ninety-one".